PS26 Effect of re-solution treatment on fatigue behaviour of nitrogen-gas-annealed type 304

Abstract

The effect of re-solution treatment on the fatigue behavior in nitrogen-gas-annealed type 304 was investigated. Re-solution treatment was performed at 1200℃ for 1h after the nitrogen-gas-annealed treatment at 1200℃ for 30h, resulting in the decomposition of chromium nitrides (CrN). In laboratory air, the fatigue strengths of re-solution treated specimens were higher than those of untreated ones. The improvement of fatigue strengths was due to the solid solution of nitrogen into the matrix by the re-solution treatment. In 3%NaCl solution, the fatigue strengths of re-solution treated specimens were much lower than that of the untreated ones because the sensitization took place.